Dual-Motor Vehicle Torque Control Using Wheel Vibration Slip Estimation
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Solution Overview
Problem
Conventional vehicle body speed estimation methods for dual-motor electric vehicles are inaccurate, leading to difficulties in calculating wheel slip and maximizing acceleration performance, as they rely on estimating speed based on the wheel experiencing slip, which results in a difference between estimated and actual vehicle speed.
Innovation Solution
A driving force control apparatus with a front-wheel driver, rear-wheel driver, wheel speed detector, wheel vibration calculator, estimated speed calculator, slip-rate calculator, and driving controller that adjusts driving force based on wheel vibration values to accurately estimate vehicle speed and prevent wheel slip, allowing independent control of front and rear wheels to maintain acceleration performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional vehicle body speed estimation method is used, then the system is simple, but the estimated speed is inaccurate and differs from actual vehicle speed
Solution Approach 1:
The patent introduces wheel vibration values as an intermediary parameter to improve speed estimation accuracy. The vibration calculator computes vibration values from wheel speed data, and the estimated speed calculator uses these vibration values as a mediator to correct the conventional speed estimation, reducing the error between estimated and actual vehicle speed without requiring additional sensors.
Solution Approach 2:
The patent replaces the conventional mechanical speed estimation method (based solely on wheel speed sensors) with a computational approach that substitutes physical measurement limitations with signal processing. By using vibration analysis and computational algorithms, the system achieves higher accuracy without adding mechanical components.
2Speed
If driving torque is increased for rapid acceleration, then acceleration performance is improved, but wheel slip occurs more frequently
Solution Approach 1:
The patent implements a feedback control mechanism where the slip-rate calculator continuously monitors wheel slip conditions and feeds this information back to the driving controller. The controller adjusts driving torque based on real-time slip rate feedback, reducing torque when slip is detected and restoring it when grip is regained, thereby maintaining acceleration performance while preventing excessive wheel slip.
Solution Approach 2:
The patent applies dynamic control of driving torque rather than a fixed torque value. The system continuously adapts the driving force based on real-time wheel slip conditions, road surface grip variations, and vehicle acceleration state, allowing the vehicle to maintain optimal acceleration performance across changing conditions without sustained wheel slip.
3Productivity
If independent control of front and rear wheel drivers is implemented, then acceleration performance is maximized, but the control system becomes more complex
Solution Approach 1:
The patent segments the vehicle's driving system into independent front-wheel and rear-wheel drive units, each with its own driver and control parameters. This segmentation allows independent optimization of front and rear wheel torque distribution to maximize acceleration performance while managing complexity through modular control architecture.
Solution Approach 2:
The patent implements a universal control framework that manages both front and rear wheel drivers through a single integrated control system. The driving controller performs multiple functions including slip rate calculation, torque distribution optimization, and coordinated control of both motors, reducing overall system complexity despite independent wheel control.
Data Source
AI summary
According to an embodiment of the present disclosure, a driving force control apparatus for a vehicle includes: a front-wheel driver; a rear-wheel driver; a wheel speed detector; a wheel vibration calculator; an estimated speed calculator that calculates an estimated vehicle speed of the vehicle; a slip-rate calculator that calculates a slip rate of each wheel; and a driving controller that reduces a driving force of the front wheel driver or the rear wheel driver when a slip rate of each wheel is greater than a preset slip rate value. The estimated speed calculator determines that the estimated vehicle speed is greater than an actual speed of the vehicle when the vibration value calculated by the wheel vibration calculator is greater than a preset vibration value.